Nitric Oxide Synthase and Xanthine Oxidase Activities in the Spermatic Vein of Patients with Varicocele: A Potential Role for Nitric Oxide and Peroxynitrite in Sperm Dysfunction

Abstract

Our data suggest a high oxidative stress due to the release of nitric oxide synthase and xanthine oxidase within the dilated spermatic vein. The reaction resulted in dramatic formation of nitric oxide, peroxynitrite and S-nitrosothiols, which are biologically active. Formation of peroxynitrite from the reaction of nitric oxide with superoxide could be a causative factor for impaired sperm function in patients with varicocele.